21229549 has 16 divisors (see below), whose sum is σ = 24774336. Its totient is φ = 17977600.

The previous prime is 21229501. The next prime is 21229577. The reversal of 21229549 is 94592212.

It is a cyclic number.

It is not a de Polignac number, because 21229549 - 2¹¹ = 21227501 is a prime.

It is a Duffinian number.

21229549 is a modest number, since divided by 9549 gives 2122 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21229589) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19479 + ... + 20539.

It is an arithmetic number, because the mean of its divisors is an integer number (1548396).

Almost surely, 2^21229549 is an apocalyptic number.

It is an amenable number.

21229549 is a deficient number, since it is larger than the sum of its proper divisors (3544787).

21229549 is a wasteful number, since it uses less digits than its factorization.

21229549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1196.

The product of its digits is 12960, while the sum is 34.

The square root of 21229549 is about 4607.5534722887. The cubic root of 21229549 is about 276.8940281990.

The spelling of 21229549 in words is "twenty-one million, two hundred twenty-nine thousand, five hundred forty-nine".